TYPE IB SECRETORY PHOSPHOLIPASE A2 IS CONTAINED IN INSULIN SECRETORY GRANULES

胰岛素分泌颗粒中含有 IB 型分泌型磷脂酶 A2

• 批准号: 6665883
• 负责人: SASANKA RAMANADHAM
• 金额: $ 15.75万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6665883
• 关键词: biological products; biomedical resource; carbohydrates; cardiovascular system; endocrine gland /system; female; hormones; human subject; lipids; male; spectrometry; biological products; biomedical resource; carbohydrates; cardiovascular system; endocrine gland /system; female; hormones; human subject; lipids; male; spectrometry

Stimulation of pancreatic islets with D-glucose induces insulin secretion from secretory granules contained within the islet ?-cells. Accumulating evidence suggests that secretory phospholipases A2 (sPLA2) may play a role in the distal events of secretory processes in many different cell types. Since intact pancreatic islets have been reported to contain sPLA2, it was of interest to determine the cellular and subcellular localization of the sPLA2 enzymes in pancreatic islets. Our findings indicate that rat pancreatic islets express mRNA for both types IB and IIA sPLA2 enzymes and mRNA for an sPLA2 membrane receptor. Immunoblotting analyses with antibodies directed against type IB sPLA2 or against type IIA sPLA2 indicate that the type IB isoform is much more abundant than the type IIA isoform in islets. Studies with purified populations of islet ?-cells prepared from dispersed islet cells by fluorescence-activated cell sorting indicate that both sPLA2 activity an d type IB sPLA2 immunoreactive protein are substantially more abundant in ?-cells than in non-?-cells. Subcellular fractionation studies indicate that sPLA2 activity and type IB sPLA2 immunoreactive protein are contained in insulin secretory granules. Stimulation of intact islets with insulin secretagogues results in the co-secretion of insulin and of sPLA2 activity and type IB sPLA2 immunoreactive protein into the incubation medium. These findings raise the possibility that type IB sPLA2 participates in the secretory process of pancreatic islet ?-cells.

用D-葡萄糖刺激胰岛诱导胰岛素 胰岛内包含的分泌颗粒的分泌？ 积累的证据表明分泌磷脂酶A2 （SPLA2）可能在分泌过程的远端事件中发挥作用 许多不同的细胞类型。 由于完整的胰岛已经 据报道包含spla2，确定 SPLA2酶在中的细胞和亚细胞定位 胰岛。 我们的发现表明大鼠胰岛 两种类型的IB和IIA SPLA2酶和mRNA的mRNA表达mRNA SPLA2膜受体。 用抗体进行免疫印迹分析 针对IB型SPLA2或针对IIA型Spla2指示 IB类型的类型比IIA类型的同工型更丰富 胰岛。 用纯化的胰岛种群进行的研究？ 通过荧光激活的细胞分类从分散的胰岛细胞中 表明两种spla2活性和I型IB SPLA2免疫反应性 蛋白质的蛋白质比蛋白质更丰富吗？ 非 - ？ - 细胞。 亚细胞分级研究表明SPLA2 活性和类型IB SPLA2免疫反应性蛋白包含 胰岛素分泌颗粒。 用胰岛素刺激完整的胰岛 秘密促进导致胰岛素和SPLA2的共归因于 活性和类型IB SPLA2免疫反应蛋白进入孵育 中等的。 这些发现增加了IB Spla2类型的可能性 参加胰岛的分泌过程？